Suchergebnisse

The p2model is a random effects model with covariates for the analysis of binary directed social network data coming from a single observation of a social network. Here, a multilevel variant of the p2model is proposed for the case of multiple observations of social networks, for example, in a sample of schools. The multilevel p2model defines an identical p2model for each independent observation of the social network, where parameters are allowed to vary across the multiple networks. The multilevel p2model is estimated with a Bayesian Markov Chain Monte Carlo (MCMC) algorithm that was implemented in free software for the statistical analysis of complete social network data, called StOCNET. The new model is illustrated with a study on the received practical support by Dutch high school pupils of different ethnic backgrounds.

Il presente elaborato ha il fine di analizzare il più grave scandalo politico mai scoppiato in Italia, ovvero la scoperta della Loggia massonica Propaganda 2 (P2). Quest'ultima fu una potentissima Loggia massonica coperta, ovvero segreta, che, sotto la supervisione del Venerabile Licio Gelli, riuscì ad affiliare centinaia di "fratelli" appartenenti alle più alte cariche dello Stato, attivi in special modo fra le forze dell'ordine, la sfera economica e il mondo politico. Allo scoperchiamento, attuato grazie ai lavori della magistratura di Milano, seguì presto un autentico terremoto istituzionale, che portò alla costituzione di una Commissione Parlamentare di inchiesta avente il compito di indagare sulle vere finalità della Loggia. Queste ultime si rivelarono ben presto assai intricate, ed emerse sempre più pesantemente il ruolo esercitato dalla P2 in alcuni degli episodi più oscuri della storia del Paese. L'elaborato si propone dunque di esaminare il fenomeno in una doppia prospettiva, rapportando le vicende della Loggia all'evolversi dei due contesti entro cui ebbe modo di svilupparsi: rispettivamente, la politica italiana degli anni Settanta da un lato e la Massoneria dall'altro.

Brain development requires the interaction of complex signaling pathways, involving different cell types and molecules. For a long time, most attention has focused on neurons in a neuronocentric conceptualization of central nervous system development, these cells fulfilling an intrinsic program that establishes the brain's morphology and function. By contrast, glia have mainly been studied as support cells, offering guidance or as the cells that react to brain injury. However, new evidence is appearing that demonstrates a more fundamental role of glial cells in the control of different aspects of neuronal development and function, events in which the influence of neurons is at best weak. Moreover, it is becoming clear that the function and organization of the nervous system depends heavily on reciprocal neuron-glia interactions. During development, neurons are often generated far from their final destination and while intrinsic mechanisms are responsible for neuronal migration and growth, they need support and regulatory influences from glial cells in order to migrate correctly. Similarly, the axons emitted by neurons often have to reach faraway targets and in this sense, glia help define the way that axons grow. Moreover, oligodendrocytes and Schwann cells ultimately envelop axons, contributing to the generation of nodes of Ranvier. Finally, recent publications show that astrocytes contribute to the modulation of synaptic transmission. In this sense, purinergic receptors are expressed widely by glial cells and neurons, and recent evidence points to multiple roles of purines and purinergic receptors in neuronal development and function, from neurogenesis to axon growth and functional axonal maturation, as well as in pathological conditions in the brain. This review will focus on the role of glial and neuronal secreted purines, and on the purinergic receptors, fundamentally in the control of neuronal development and function, as well as in diseases of the nervous system. © 2013 del Puerto, Wandosell and Garrido. ; Spanish Government (SAF2009-12249-C02-02, SAF2012-39148-C03-03, SAF2012-39148-C03-01) ; Peer Reviewed

Frontiers in Cellular Neuroscience OCT (2013): 197 this Document is Protected by copyright and was first published by Frontiers. All rights reserved. It is reproduced with permission ; Brain development requires the interaction of complex signaling pathways, involving different cell types and molecules. For a long time, most attention has focused on neurons in a neuronocentric conceptualization of central nervous system development, these cells fulfilling an intrinsic program that establishes the brain's morphology and function. By contrast, glia have mainly been studied as support cells, offering guidance or as the cells that react to brain injury. However, new evidence is appearing that demonstrates a more fundamental role of glial cells in the control of different aspects of neuronal development and function, events in which the influence of neurons is at best weak. Moreover, it is becoming clear that the function and organization of the nervous system depends heavily on reciprocal neuron-glia interactions. During development, neurons are often generated far from their final destination and while intrinsic mechanisms are responsible for neuronal migration and growth, they need support and regulatory influences from glial cells in order to migrate correctly. Similarly, the axons emitted by neurons often have to reach faraway targets and in this sense, glia help define the way that axons grow. Moreover, oligodendrocytes and Schwann cells ultimately envelop axons, contributing to the generation of nodes of Ranvier. Finally, recent publications show that astrocytes contribute to the modulation of synaptic transmission. In this sense, purinergic receptors are expressed widely by glial cells and neurons, and recent evidence points to multiple roles of purines and purinergic receptors in neuronal development and function, from neurogenesis to axon growth and functional axonal maturation, as well as in pathological conditions in the brain. This review will focus on the role of glial and neuronal secreted purines, and on the purinergic receptors, fundamentally in the control of neuronal development and function, as well as in diseases of the nervous system ; This work was supported by GrantsSAF2009-12249-C02-02, SAF2012-39148-C03-03, and SAF2012-39148-C03-01 from the Spanish Government

The need for bone grafts is high, due to age-related diseases, such as tumor resections, but also accidents, risky sports, and military conflicts. The gold standard for bone grafting is the use of autografts from the iliac crest, but the limited amount of accessible material demands new sources of bone replacement. The use of mesenchymal stem cells or their descendant cells, namely osteoblast, the bone-building cells and endothelial cells for angiogenesis, combined with artificial scaffolds, is a new approach. Mesenchymal stem cells (MSCs) can be obtained from the patient themselves, or from donors, as they barely cause an immune response in the recipient. However, MSCs never fully differentiate in vitro which might lead to unwanted effects in vivo. Interestingly, purinergic receptors can positively influence the differentiation of both osteoblasts and endothelial cells, using specific artificial ligands. An overview is given on purinergic receptor signaling in the most-needed cell types involved in bone metabolism&mdash ; namely osteoblasts, osteoclasts, and endothelial cells. Furthermore, different types of scaffolds and their production methods will be elucidated. Finally, recent patents on scaffold materials, as wells as purinergic receptor-influencing molecules which might impact bone grafting, are discussed.